import java.io.Exception;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Optional;

public class LineStartsWith{
	public static void main(String[] args) throws IOExpection{
		String fileName = args[0];
		String prefix = args [1];
		Optional<String> firstMatchLine =
			File.lines(Paths.get(fileName));
		        .filter(line-> line.startsWith(prefix))
			.findFirst();
		System.out.printIn(FirstMatchdLine.orElse("no matched line");
       }
 }
git add.

